The present invention relates to a light radiator and relates more particularly to a light radiator for receiving light transmitted through a fiber optic cable and for radiating the same in such a way as to get a desired light distribution.
The present applicant has previously proposed various methods and systems to focus solar rays or artificial light rays by using lenses or the like to guide the focused light rays into a fiber optic cable and to transmit them to any place where the light is needed for illumination or for other purposes as for example to promote the cultivation of plants; for the propagation of chlorella; for giving beauty treatments through sunbathing; for giving medical treatments through light radiation etc. If light rays are emitted from the cut-off end of a fiber optic cable, they can be radiated only within a small angle of radiation of about 46.degree. since focused light rays have a certain directivity. Therefore, desirable light radiation for the above-mentioned purposes may not be obtained if light is directly emitted from the cut-off end of the fiber optic cable. In order to solve this problem, the present applicant has also proposed various kinds of light radiators which can effectively diffuse the light rays transmitted through a fiber optic cable and to radiate the same to any desired space.
A light radiator previously proposed by the present applicant comprises, for example, a light guide and a groove that is spirally cut on the surface of the light guide.
The light introduced into the light guide is reflected on a grooved portion thereof and effectively radiated therefrom for use as illumination and for other intended purposes.
In this case, if the spiral groove is made in such a way that the spiral pitch gradually becomes narrow or the groove itself gradually deepens in the direction of the light then a substantially uniform radiation of the light from the whole body of the light guide may be realized.